Fluid-powered heat exchanger apparatus for cooling electronic equipment

ABSTRACT

A heat exchanger is located in an electronic equipment enclosure as part of a system for transporting heat away from the electronic equipment. The heat exchanger comprises first and second coolant loops. The amount of electrical power consumed within the equipment enclosure is reduced by employing the motive force of the fluid being pumped through the first cooling loop to move fluid through the second cooling loop without the use of an electric motor. The velocity of fluid flowing through the second coolant loop is varied by controlling the velocity of fluid flowing through the first coolant loop.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to: 1) U.S. provisional application, Ser. No. 61/356,016, filed Jun. 17, 2010, which application(s) are all also incorporated by reference herein in their entirety.

FIELD OF TECHNOLOGY

This disclosure relates generally to the technical fields of cooling fluids, and in one example embodiment, this disclosure relates to an apparatus for transferring heat between two coolant loops.

BACKGROUND Technical Field

The present invention relates to the use of fluids to cool electronic equipment. Such equipment generally includes computers, communications equipment, and data storage devices. Such equipment is typically housed within an equipment rack, the standard 19-inch rack being commonly employed. Fluids distributed to electronic equipment are typically used as a coolant for removing heat generated by the electronic circuits. The most commonly used coolant is air, but liquid coolants such as water are also employed, especially in applications where high amounts of heat are being generated in a compact space (high heat density). There is a movement in the computing industry toward increasing cooling system efficiency by close-coupling of liquid coolants, bringing the liquid coolant as close as possible to the source of the heat.

Background of the Invention

As liquid coolants are brought into proximity of electronic equipment, it is often desirable to attain fluid isolation between the primary source of coolant (facilities coolant) and the coolant being delivered to the equipment. This isolation is achieved by a heat exchanger, where the heat conducted by an equipment coolant loop is transferred to a facilities coolant loop. For equipment housed in racks, the heat exchanger is typically located outside the rack, and is sized large enough to facilitate cooling of many articles of equipment in multiple racks. Coolant is moved through the facilities coolant loop by means of remotely located facilities pumping equipment, and the heat exchanger unit provides a pump for moving fluid through the equipment coolant loop. The heat exchanger employs an electric motor which in addition to providing motive force to drive the pump, draws some amount of electrical power, generates some amount of heat, and has the potential of creating electromagnetic radiation, potentially interfering with electronic equipment. Servicing heat exchangers often requires specialized knowledge and tools related to fluid handling systems.

SUMMARY OF THE INVENTION

The current invention seeks to improve the suitability of heat exchangers for operation in proximity to electronic equipment by:

1. eliminating heat generated by electric motors

2. eliminating electromagnetic interference from motors

3. providing failsafe redundancy for heat exchanger systems

4. providing scalability for heat exchanger systems

5. enhancing serviceability of heat exchanger systems

The first two objectives are achieved by removing the electric motor usually associated with a heat exchanger pumping system, and replacing it with a turbine. The turbine is driven by the facilities coolant loop, and the turbine runner is mechanically coupled to the pump impeller on the equipment coolant loop. The remaining objectives are attained by integrating the majority of heat exchanger system components into a unified body, making the system compact and easily adapted to the standard 19-inch rack mounting system. The compact form of the module makes it possible to mount multiple heat exchangers into a rack, whereby the number included can be scaled to the heat load of the rack, plus any additional units desired to provide system redundancy. Rack-mounted heat exchangers can be quickly and easily swapped out of the rack for outside servicing by qualified personnel.

The methods, systems, and apparatuses disclosed herein may be implemented in any means for achieving various aspects of the present disclosure. Other features will be apparent from the accompanying drawings and from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:

FIG. 1 depicts a cut-away view of a rack-mountable heat exchanger where the main body of the unit comprises a fluid reservoir with an integrated turbine-driven pump assembly.

DETAILED DESCRIPTION

A preferred embodiment of the invention would be a heat exchanger unit for facilitating the removal of heat from an electronic equipment rack. The heat exchanger mounts into the equipment rack along with the equipment being cooled. The heat exchanger occupies a 2U rack space, and multiple heat exchanger units may be mounted in the rack, providing scalability and cooling system redundancy.

FIG. 1 shows a cut-away view of the heat exchanger. The outer shell of the unit constitutes a containment reservoir (101) for the equipment coolant. A first set of fluid connection ports function as the equipment coolant loop supply (103) and equipment coolant loop return (102). The equipment coolant enters the return connection port (102), flows through a system of channels formed by internal baffles (110), and is pumped out the equipment coolant supply port (103) by the force of a pump impeller (107). A second set of fluid connection ports functions as the facilities coolant loop supply (104) and facilities coolant loop return (105). The facilities pumping system forces coolant into the facilities supply coolant port (104), and through a turbine runner (106), proportional fluid control valve (112), and internal tubing (109), before exiting the facilities return coolant port (105). The internal tubing takes a serpentine path through the equipment coolant reservoir, thus facilitating heat transfer between the two coolant loops. The rotational force of the turbine runner is directly coupled to the pump impeller by a shaft (108). The velocity of coolant flowing through the equipment coolant loop is proportional to the velocity of the coolant passing through the facilities coolant loop, and is throttled by the proportional fluid control valve to attain the desired flow rate. Alternately, the valve could be disposed to bypass the turbine and control the flow rate by shunting some amount of coolant past the turbine instead of throttling coolant The valve is actuated by a stepper motor (113) mounted to the back of the unit and mechanically coupled to the valve housing. The valve, turbine runner, and pump impeller housings are all integrated internally into the reservoir. The unit is secured to the equipment rack by mounting brackets (111) at each corner.

The invention has been described for use with liquid coolants on both coolant loops, but the invention may be adapted for alternate combinations of coolants. For example, the equipment coolant loop could employ air as the coolant, in which case the pump impeller would be replaced with fan blades. Other variations such as the use of a two-phase coolant may be exercised by those skilled in the art.

While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and changes therein may be effected by those skilled in the art. For example, methods and operations described herein can be in different sequences than the exemplary ones described herein, e.g., in a different order. Thus, one or more additional new operations may be inserted within the existing operations or one or more operations may be abbreviated or eliminated, according to a given application, so long as substantially the same function, way and result is obtained. Accordingly, it is intended by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. 

1. An apparatus for transferring heat generated by electronic equipment, comprising a heat exchanger, wherein a first fluid flow passageway is in thermal communication with a second fluid flow passageway, whereby heat is transferred between first and second fluids contained respectively therein, and further including a turbine in fluid communication with the first fluid flow passageway, and a pump in fluid communication with the second fluid flow passageway, wherein the rotational force generated by the turbine runner is mechanically transferred to the pump impeller.
 2. An apparatus as in claim 1, in which the first fluid flow passageway in fluid communication with at least one facilities coolant system constitutes a first coolant loop, and the second fluid flow passageway in fluid communication with at least one article of electronic equipment constitutes a second coolant loop.
 3. An apparatus as in claim 1, in which fluid flows through the first fluid flow passageway by means of the force of an external pump.
 4. An apparatus as in claim 1, in which fluid flows through the first fluid flow passageway by means of the force of gravity.
 5. An apparatus as in claim 1, in which the second fluid passageway constitutes a fluid reservoir or plenum.
 6. An apparatus as in claim 5, in which the reservoir is disposed to prime the pump.
 7. An apparatus as in claim 5, in which the pump impeller housing is an integral part of the fluid reservoir or plenum.
 8. An apparatus as in claim 5, in which the first fluid flow passageway passes through the reservoir or plenum in fluid isolation.
 9. An apparatus as in claim 8, in which the turbine runner housing is an integral part of the fluid reservoir or plenum.
 10. An apparatus as in claim 1, in which the rotational force of the turbine runner is directly coupled to the pump impeller.
 11. An apparatus as in claim 1, in which the rotational force of the turbine runner is coupled to the pump impeller through an arrangement of gears, or by means of a belt or chain.
 12. An apparatus as in claim 1, in which the flow rate of the second fluid is adjustably controlled by varying the flow rate of the first fluid.
 13. An apparatus as in claim 12, in which the fluid flow rate is adjusted to maintain a constant temperature of the equipment being cooled.
 14. An apparatus as in claim 12, in which the fluid flow rate is adjusted to optimize the energy efficiency of the cooling system in response to a measurement of the heat load or power consumption of the electronic equipment being cooled.
 15. An apparatus as in claim 1, further including at least one electrically-operated fluid control valve, or fluid flow rate sensor, or fluid temperature sensor in fluid communication with at least one fluid flow passageway.
 16. An apparatus as in claim 15, further including an electronic control module in electrical communication with at least one electrically actuated fluid control valve, or fluid flow rate sensor, or fluid temperature sensor.
 17. An apparatus as in claim 16, in which the control module comprises a digital processor unit and memory for storing a digital control program, which is executed by the processor unit for controlling the module, and includes a communication link interconnecting the control module and a computer, or interconnecting a plurality of control modules disposed to a plurality of heat exchanger modules.
 18. An apparatus as in claim 1, in which the impeller constitutes fan blades, whereby air is moved through the second fluid flow passageway.
 19. An apparatus as in claim 1, in which the module is disposed to an electronic equipment chassis or equipment rack.
 20. An apparatus as in claim 1, in which the fluid passing through the first fluid passageway is a liquid coolant. 